Various formulations have been used by industry to provide barrier coatings for metal surfaces to protect those surfaces from corrosion and rust. Recently, formulations have included compounds called "rust converters" which are primarily based upon tannic or phosphoric acids, along with various other acids well known in the art. However, these acid compounds are susceptible to leaching and thus the protection is lost. Oxime based rust converter compounds have replaced the tannic and phosphoric acid compounds in rust inhibiting compositions due to their superior rust converting properties.
The formulations presently utilized to protect metal surfaces contain the rust coverter compounds in a base coating system. Typically this system is a latex base paint, however other resin base systems are known. These latex base paint systems are formulated with relatively high levels of "fillers", that is, compounds such as dyes, pigments, clays, carbonates, talc, phosphates, titanium dioxides, whiting agents, iron oxides, sulfates, silica, and the like. These fillers serve various functions, however they also severely restrict the elastic properties of the coating once it is applied to the metal surface. The coating is then prone to cracking and peeling upon exposure to ambient environmental conditions. Therefore, the coating will fail to protect the surface at the crack areas, and those areas proximate thereto, causing the surface to rust and corrode.
The formulations currently used to protect metal surfaces from rust and corrosion, containing high amounts of fillers, also present severe environmental and worker safety problems associated with their use. Removal of these formulations when they begin to crack and peel requires either chemical solvents or extensive amounts of labor in the form of sanding and sandblasting. The resulting waste from these processes is either toxic, volatile, or a combination of both and is therefore undesirable.
A critical need therefore exists to provide a rust inhibiting and corrosion resistant formulation that has superior elasticity properties such that it will not crack or peel upon exposure to ambient environmental conditions. Also, techniques are required for applying the coating to the surfaces to provide for ease of removal while avoiding toxicity or volatility problems.